Abstract: A method and apparatus for simultaneous testing of one or more hydraulic control systems, each system having a hydraulic pressure pump whose high-pressure end is connected to a first tank in which a first piston element having a relatively small surface is movable and whose low-pressure end is connected to a second tank in which a second sealing element, which has a relatively large surface and is coupled with the first piston element, is movable in such a way that under normal working conditions a constant compression ratio is maintained in the system and each individual system includes at least one working unit between the high-pressure end and the low pressure end while, for use on a test unit with a pressure pump of its own, its high-pressure end is connected to the high-pressure end of each system to be tested and the low-pressure end is connected by way of a tank to the low-pressure end of each system to be tested, at least one pressure regulator for each system being inserted between the tank to the te

Abstract: A series regulating transistor supplying voltage to a supply bus from a vehicular battery in which circuitry samples voltage from the supply bus for generating a correction signal for controlling operation of the regulating transistor. A first switching transistor of a starting circuit biases the regulating transistor into a conductive state in response to the connection of the battery to the apparatus and a second switching transistor switches the first switching transistor OFF responsive to the voltage level developed on the supply bus.

Abstract: A test stand for an internal combustion engine testing system is disclosed. The test stand permits the engine to substantially freely vibrate such that engine imbalance can be measured. The test stand includes a cradle and a support assembly, having a housing and an inflatable bladder member. The bladder member supports the cradle during the testing operation.

Abstract: An amplitude detection circuit utilizing a pair of polarity reversing amplifiers is disclosed.

Abstract: The disclosure describes an improved apparatus and method for displaying and printing the results of an analysis of an internal combustion engine. The results simultaneously are displayed on a cathode ray tube (CRT) face and are written into a buffer memory of a printer. An operator can move a cursor to the line of the CRT display for which special printing is desired. By pushing an ENTER switch, the operator causes a problem flag to be displayed on the screen at the desired line. The information displayed on the CRT face then is printed, together with an additional message indicating a possible vehicle problem. The line designated by the problem flag is printed in a modified ink color to indicate the source of the possible vehicle problem.

Abstract: The present invention is a metering system including a signal conditioning circuit, processor and output system. The signal conditioning circuit receives a state-indicating signal and responsively produces a repetitive digital signal compatible with the processor. The processor samples the repetitive digital signal, determines the period thereof and produces an output signal having a value related to the state-indicating signal. The output system displays the value of the output signal.

Abstract: The disclosure describes improved apparatus for driving a load, such as a meter, in proportion to a source voltage produced by a signal generator. The apparatus includes a non-differential gain stage for generating an amplified voltage between a gain stage output and one of the generator outputs. The non-differential gain stage is followed by a differential stage which generates a rereferenced voltage between the differential stage output and one of the load terminals. The rereferenced voltage is proportional to the amplified voltage and is substantially independent of any offset voltage between the one generator output and the one load terminal. By coupling the rereferenced voltage to the load, the load voltage is made proportional to the source voltage irrespective of changes in the offset voltage between the one generator output and the one load terminal. The load may include a meter and an amplifying stage for ranging and zeroing the meter.

Abstract: An apparatus for diagnosing the operating state or condition of various components of an automotive engine is disclosed herein. The apparatus generates diagnostic signals representing the relationship between engine operating parameters and engine specifications. The diagnostic signals are selectively processed according to a test matrix to determine the operating state of each engine component. A diagnostic message then identifies which, if any, of the components requires repair or replacement.

Abstract: The disclosure describes an improved automated engine diagnosing device employing a digital data processor computer and a cathode ray tube display monitor which displays engine parameter (i.e., condition) values in alphabetic, numeric, and graphical form. Some data is accumulated from the engine by means of direct digital measurements, whereas other data is obtained from the engine by an analog-to-digital converter. The data is then processed by the computer and displayed on the cathode ray tube display monitor.

Abstract: An improvement in an analog oscilloscope for an automotive ignition analyzer is disclosed. The improvement is a short store circuit which enables substantially complete display of the secondary coil voltage, including the peak amplitude of the firing line voltage.

Abstract: The disclosure describes an analyzer controlled by a microprocessor having a memory for diagnosing a vehicle engine. Engine specifications are read into the analyzer by a card bearing: (1) specifications of the engine printed in alpha-numeric form; and (2) a machine-readable code representing a portion of the specifications. A code reader reads the code on the card and converts it into electronic digital signals. The digital signals are converted to a form usable by the microprocessor so that the specifications can be stored in the memory. During analysis, information can be written on the card and stored for use during a subsequent analysis.

Abstract: The disclosure describes an improved tachometer for displaying the speed of an engine which produces ignition pulses. The tachometer includes a pulse-forming circuit, a meter, and a capacitor connected in series with the meter. A rectifier enables the transmission of a current pulse through the capacitor and meter in response to each timing pulse. A discharge device momentarily interconnects the opposed plates of the capacitor in response to the terminal of each timing pulse, whereby the voltage on the capacitor is dissipated. The meter indicates the speed of the engine by responding to the frequency of the current pulses. The discharge device includes a diode and transistor connected across the capacitor.

Abstract: The disclosure describes improved apparatus for creating a delay for stroboscopes which corresponds to a fixed rotational angle of an engine and is independent of the rotational speed of the engine. The delay is created by charging a capacitor by means of a first current source and discharging the capacitor by means of a second current source.

Abstract: The disclosure describes an improved apparatus for measuring the dwell of an engine ignition system employing points which close to conduct current through a coil and which open to generate an ignition signal. The apparatus enables the pointer of a meter to move upscale for increasing dwell, thereby simplifying the reading of the meter. A shaping circuit shapes the ignition signal to form a charging pulse which stores energy in a charging capacitor. When the points are closed, the energy stored in the capacitor is transmitted through the meter by a switching circuit so that the pointer advances away from its zero position as the dwell of the ignition system increases.

Abstract: An apparatus for measuring the dwell of an automobile ignition system is disclosed. The dwell measuring apparatus is applicable to conventional and solid state ignition systems. The apparatus analyzes the primary coil ignition waveform and generates a signal proportional to the dwell ratio, based upon the amount of time the primary voltage is approximately zero.